Projectile with multiple effect

ABSTRACT

A multiple effect projectile having two incendiary charges connected by a bore and an explosive charge behind the second incendiary charge so that the explosive charge is detonated without a separate fuse.

United States Giljarhus et a1.

atet

[54] PROJECTILE WITH MULTIPLE EFFECT [72] Inventors: Gunnar Giliarhus;Hans Vien, both of Raufoss, Norway [21] Appl.No.: 866,662

[52] US. Cl ..l02/52, 102/60, 102/66 [51] Int. (1 F42b 13/04 [58] Fieldof Search 102/52, 66, 6, 90, 60, 56

[56] References Cited UNITED STATES PATENTS 3,096,715 7/1963 Dufour..102/52 3,208,385 9/1965 Perniss ..l02/66 s: s 2! i /2 [15] 3,677,181July 18, 1972 Primary Examiner-Samuel W. Engle Attomey-Stevens, Davis,Miller & Mosher ABSTRACT A multiple effect projectile having twoincendiary charges connected by a bore and an explosive charge behindthe second incendiary charge so that the explosive charge is detonatedwithout a separate fuse.

4 Claims, 1 Drawing Figure Patented July 18, 1972 INVENTCRS GUNNARGILJARHUS HANS VIEN TTORNEYS PROJECTILE WITH MULTIPLE EFFECT The presentinvention relates to projectiles having multiple eflect for use inammunition to be fired from aircraft guns, anti-aircraft guns and groundartillery as well as for navy purposes, of small caliber, for instanceup to 40 mm. The basic principle of the invention may, however, also beadapted to greater calibers.

Incendiary projectiles are known being charged with incendiary materialin both of the main components of the grenade, that is the top portionand the body portion. An incendiary projectile having such aconstruction, however, has a strongly limited use in that it may onlysubjected to relatively small G- values. Consequently ammunition of thistype and when used in modern weapons with high initial velocity and highgas pressures (P will be self-igniting in a gun because of set back ofthe incendiary charge of the top portion against the incendiary chargeof the body portion. Such untimely igniting action is a critical faultin the ammunition.

Furthermore, the commonly known types of incendiary grenades have thedrawback that, upon impact with thinwalled objects, such as the morevulnerable parts of an aircraft-wing, the grenade body does notdisintegrate into fragments but will penetrate straight through theobject in its initial form with minimal damaging effect.

It is known to attempt eliminau'on of this drawback by positioning ahigh explosive bursting charge inside the nose portion of the grenade ontop of the incendiary charge. By impact the grenade will thus in athin-walled object, such as parts of an aircraft, be subjected tofragmentation and the body fragments together with the incendiary chargewill be sprayed into the target with great damaging effect. This knownprinciple is based on the condition that the grenade is provided with afuse, the initial and booster charge of which will bring about thedetonation of the explosive charge of the grenade.

it is furthermore known for heavier and more compact targets, forinstance light armored vehicles, fuel tanks, ships hulls and the like,to use plain armor piercing projectiles or armor incendiary projectiles.The main component in such a projectile type is a compact hardened steelcore having great penetrating ability through steel and armor plates.However, this type of projectile has also substantial drawbacks, forinstance that the armor core usually will not disintegrate onpenetration and one therefore fails to achieve the damaging efi'ect offragments inside the target. Furthermore, when using such projectilesthe armor core will during penetration of the target peel off theincendiary charge, the top portion and the like. The substantial portionof the incendiary effect will thus take place on the front side(externally) of the target and not penetrate into same as was desired.Additionally such a projectile will at the moment of impact on aslanting target, with impact angles smaller than approx. 30, skid offand consequently have no effect at all.

It is thus a main object of this invention to make available aprojectile which as such forms a combination of several new principlesin order to achieve various forms of damaging effects in a variety oftargets, such as incendiary eflect, fragment effect and penetratingeffect. A further object of the invention is to provide a projectilehaving multiple efi'ects and which eliminates all of the above desireddrawbacks.

This is achieved with a projectile having multiple efiects, comprisingelements for incendiary effect and fragmentary effect as well as greatpenetrating capacity and which at the same time may be provided with perse known tracing elements and self-destruction elements, acharacteristic feature of the invention being that the fragmentaryeffect is achieved by means of an explosive charge positioned behind afirst and second incendiary charge, said explosive charge beingdetonated without any fuse means. Another feature of the inventionresides in that the first incendiary charge portion positioned in thetop portion is supported by a disc having left hand threads and acentral bore through which the secondary incendiary charge is ignited.This supporting disc should be designed to stand very high G-values.

Particularly the feature comprising the explosive charge being detonatedwithout any fuse means is obviously advantageous because the projectileor grenade may be supplied or filled with a considerably greaterquantity of incendiary charge which means that it is not necessary toreserve any space for fuse means and booster charge. In addition to thedesired fragmentary efi'ect, a maximum of incendiary effect is thusachieved. It is further of substantial economic importance that thistype of grenade may be detonated without any fuse means because the fusemeans as such usually represents nearly 50 percent of the total costs ofthe grenade for small caliber ammunition.

in the drawing is shown an embodiment of a projectile according to theinvention, in longitudinal section.

With reference to the drawing a projectile according to the inventioncomprises a top portion 1 and projectile body portion 2, each of saidmain portions containing an incendiary charge 3 and 4 respectively. Theprojectile body portion 2 furthermore comprises internally an explosivecharge 5, a socalled self-destructing means 6 with associated detonatingmeans 7 and a tracer means 8 with associated igniting means 9. Theprojectile is further completed rearwardly by means of a sealing disc 11and a steel ring 12, it being understood that the tracer meansandself-destructing means for certain purposes may be omitted.

The first incendiary charge 3 comprised in the top portion 1 ismaintained in position during firing of the projectile by a supportingdisc 13 which by means of left hand threads has been screwed into thetop portion 1. The supporting disc 13 has a central bore or opening 14through which the secondary incendiary charge 4 is ignited. Theincendiary charge 3 contained in the top portion 1 has a rearwardlysupporting surface formed with a bridge construction 15 for the purposeof withstanding the shearing forces caused by setback of the charge 3and thus prevents untimely ignition. The supporting disc 13 is designedand calculated to stand very high G-values of at least 150,000 withoutuntimely ignition of the incendiary charge.

This incendiary charge is ignited by impact on a target, the ignitionbeing initiated through friction, shock and heat through distortion ofthe nose by the impact.

The explosive charge 5 positioned in the body portion 2 directly beneaththe second incendiary charge 4 is detonated without any fuse means butby means of the second incendiary charge 4 and this results in the saidadvantages comprising larger space for filling with incendiary chargesinside the projectile besides substantially lower production costs.Furthermore, the detonation of the explosive charge 5 is delayed throughthe incendiary charges in such a way that the projectile also isprovided with a greater piercing effect compared with explosive grenadesby an appropriate choice of materials in the top portion 1 and the bodyportion 2 and by the fact that the total kinetic energy of theprojectile is utilized contrary to the explosive grenades where theenergy of the explosive is used.

The elements for tracing and self-destruction arranged in the projectileare per se known and should not require further explanation ordescription in this connection.

The above mentioned drawbacks in known projectiles such as armorpiercing and incendiary projectiles, particularly the fact that same arenot sufficiently disintegrated to cause damaging effects by fragmentsinside the target and that the incendiary charge, the top portion andthe like are peeled off by the impact, have been eliminated in theprojectile according to the invention. This is due to the form given tothe top portion and projectile body in cooperation with the fact that asuitable choice of material for the same parts has proved by numeroustests to give the very surprising and advantageous result that theprojectile will straighten itself and break through the target surfaceby impact on sloping targets through friction and braking effect in thetop portion against the target surface. Simultaneously the incendiarycharge above the explosive charge will provide a delay in thedetonationof the latter in such a way that the total kinetic energy of theprojectile is utilized for the piercing work before the detonation andthe disintegration of the projectile body. Furthermore, the projectilein the final phase of penetrating a steel plate will also partlydisintegrate into fragments which will simultaneously blow or stamp outa hole having twice the size of the respective caliber. In addition tothe grenade body fragments even fragments from the steel plate willpenetrate into the target and cause great damaging effect. Because ofthe already mentioned piercing eflect, the incendiary charge will not bepeeled off on the front side of the target, but on the contrary will besprayed into same together with the fragments and having full incendiaryeffect.

The above described effects have been proved during a large number oftests with the projectile according to the invention and thus are notonly theoretical results.

We claim:

I. A projectile having multiple effects comprising: an elongated casingwhich includes a tapered nose section anda base section for containingat least two charges disposed longitudinally behind the nose section,said base section having an open end provided with an annularpenetrating shoulder of hardened material of a diameter approximatingthe longest diameter of the nose, said nose section being formed of asofter material than the base section and being provided with an annularsleeve of a diameter to extend within the base section to secure the twosections together; a first incendiary charge in the nose sectionadjacent the end thereof; a second incendiary charge disposed within thesaid base section back of the shoulder; a partition between said firstand second incendiary charges having means therein for controlling theignition of the second incendiary; an explosive charge in the basesection immediately rearwardly of the second incendiary positioned to bedetonated by said second incendiary without any separate fuse; wherebythe projectile is safe during loading and firing, the incendiarymaterial being in two charges tending to relieve any undesirable initialcompacting thereof with the incendiary material in the nose sectionbeing ignitable upon contact with a relatively readily penetrablesurface while the shoulder of the base section is adapted to penetraterelatively difficultly penetrable surfaces.

2. The projectile of claim 1 in which the partition is a disc supportingthe first incendiary and the means for controlling the ignition of thesecond incendiary is a bore passing centrally through the disc. 7

3. The projectile of claim 2 in which the supporting disc is constructedto withstand very high G forces.

4. The projectile of claim 2 in which said first incendiary charge has asupporting bottom surface in contact with said disc with a bridgeconstruction to absorb shearing forces.

1. A projectile having multiple effects comprising: an elongated casingwhich includes a tapered nose section and a base section for containingat least two charges disposed longitudinally behind the nose section,said base section having an open end provided with an annularpenetrating shoulder of hardened material of a diameter approximatingthe longest diameter of the nose, said nose section being formed of asofter material than the base section and being provided with an annularsleeve of a diameter to extend within the base section to secure the twosections together; a first incendiary charge in the nose sectionadjacent the end thereof; a second incendiary charge disposed within thesaid base section back of the shoulder; a partition between said firstand second incendiary charges having means therein for controlling theignition of the second incendiary; an explosive charge in the basesection immediately rearwardly of the second incendiary positioned to bedetonated by said second incendiary without any separate fuse; wherebythe projectile is safe during loading and firing, the incendiarymaterial being in two charges tending to relieve any undesirable initialcompacting thereof with the incendiary material in the nose sectionbeing ignitable upon contact with a relatively readily penetrablesurface while the shoulder of the base section is adapted to penetraterelatively difficultly penetrable surfaces.
 2. The projectile of claim 1in which the partition is a disc supporting the first incendiary and themeans for controlling the ignition of the second incendiary is a borepassing centrally through the disc.
 3. The projectile of claim 2 inwhich the supporting disc is constructed tO withstand very high Gforces.
 4. The projectile of claim 2 in which said first incendiarycharge has a supporting bottom surface in contact with said disc with abridge construction to absorb shearing forces.